Determination of the air and crop flow behaviour in the blowing unit and spout of a pull-type forage harvester

The energy requirements of forage harvesters can be quite high and can sometimes determine the size of tractor needed on a farm. Therefore, improving the energy efficiency of the forage harvester could allow a farm to reduce costs by using a smaller tractor that is less expensive and more efficient. The objective of this research was to increase the throwing distance of a forage harvester by modeling the flow of forage in the spout and the air flow in the blower and spout. These models can then be used to compare the efficiencies of prototype designs. The air flow in the blower and spout was modeled using the commercial computational fluid dynamics software FLUENT. The simulation results of air velocities and flow patterns were compared to experimental values and it was found that both were of the same order of magnitude with the model predicting slightly higher air velocities than those measured. The flow of forage in the spout was modeled analytically by taking into account the friction between the forage and the spout surface and the aerodynamic resistance after the forage leaves the spout. From this model, two improved prototype spouts that should theoretically result in longer throwing distances were designed. However, field testing of the two prototypes did not reveal any significant improvements over the current design. It was also found that the model under-predicted the throwing distance of one prototype by 2 % and over estimated the other by 12 %.

Name thesis:degree_name

Master of Science (M.Sc.)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Agricultural and Bioresource Engineering

Grantor

University of Saskatchewan

Year dc:date.issued

2005

Author dc:creator

• Lammers, Dennis Peter

Advisor dc:contributor.advisor

• Roberge, Martin

Committee members dc:contributor.committeemember

• Sumner, David
• Maule, Charles P.
• Laguë, Claude
• Crowe, Trever G.

• cfd
• numerical model
• analytical model
• modeling

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/10388/etd-07282005-163454

OAI identifier oai:identifier

oai:harvest.usask.ca:10388/etd-07282005-163454